let praiseBubble = document.getElementById('praise_bubble');
function addPraise() {
    const b = Math.floor(Math.random() * 6) + 1;
    const bl = Math.floor(Math.random() * 11) + 1; // bl1~bl11

    let d = document.createElement('div');
    d.className = `bubble b${b} bl${bl}`;
    d.dataset.t = String(Date.now());
    praiseBubble.appendChild(d);
}
setInterval(() => {
    addPraise();
}, 300);
